1. Field of the Invention
The present invention relates to an electrophotographic image forming apparatus which generally forms an electrostatic latent image by an electrophotographic method on an electrophotographic photosensitive member, and visualizes the electrostatic latent image with developer contained in a developing device. The invention also relates to a developing device, and a process cartridge.
In this respect, as the electrophotographic image forming apparatus, there are included, for example, an electrophotographic copying machine, an electrophotographic printer (an LED printer, a laser beam printer, or the like, for instance), and an electrophotographic facsimile apparatus, among some others.
Also, as the process cartridge, there is the one in which the electrophotographic photosensitive member and at least one of charging means, developing means, and cleaning means are integrally made into a cartridge, which is detachably mountable on the main body of an electrophotographic image forming apparatus or the one in which the electrophotographic photosensitive member and at least developing means are integrally made into a cartridge, which is detachably mountable on the main body of an electrophotographic image forming apparatus.
2. Related Background Art
Conventionally, for an image forming apparatus using the electrophotographic image forming process, there has been adopted a process-cartridge method in which an electrophotographic photosensitive member and processing means that acts on the electrophotographic photosensitive member are integrally made into a cartridge, which is detachably mountable on the main body of an electrophotographic image forming apparatus. In accordance with such process cartridge method, the apparatus can be maintained by the user in person without depending on a service engineer, hence making it possible to enhance the operativity significantly. Thus, the process-cartridge method is widely used for the electrophotographic image forming apparatus.
For the electrophotographic image forming apparatus that adopts such a process-cartridge method, the user in person replaces cartridges. For this reason, a developer-amount detecting device is considered in order to notify the user of the depletion of developer.
FIG. 10 is a view which shows one example of the conventional developer-amount detecting device. This example illustrates the state in which a conductive rod member (hereinafter referred to as xe2x80x9celectrode rodxe2x80x9d) 101 is installed in the interior of a developing container 105d of the developing device 105, and the electrode rod 101 and a developer bearing member 105a constitutes a capacitor. Thus, this method utilizes the capacitance value that changes in accordance with the amount of developer between the two electrodes 101 and 105a. 
To describe further, the electrode rod 101 is extended in the horizontal direction in the interior of the developing container 105d, and arranged to be connected with a developer-remaining-amount detecting circuit 117 in the main body of the image forming apparatus when the process cartridge is mounted, thus detecting the amount of developer and notifying the user accordingly.
The nearer to the developer bearing member 105a the electrode rod 101 is positioned, the higher the accuracy in detecting the xe2x80x9cblank areas in an imagexe2x80x9d where a bad image is created due to an insufficient amount of usable developer. Then, however, there is a tendency that the electrode rod 101 impedes the circulation of developer, and that the developer is easier to deteriorate or the circulation thereof may become inadequate, among some others.
Also, if the electrode rod is positioned away from the developer bearing member 105a, the circulation of developer is not impeded, but the detection accuracy of the xe2x80x9cblank areas in an imagexe2x80x9d tends to be lowered.
Here, in conjunction with FIG. 11, a description will be provided of the relationship between the toner amount in the developing container 105d and the capacitance to be detected (the voltage value may also be usable equally). The capacitance changes not at all or by a small amount until the toner amount is reduced to a predetermined amount, and changes rapidly thereafter.
The present invention is designed with the further development of such conventional art as has been described above.
It is an object of the invention to provide a developing device capable of enhancing the detection accuracy of the toner-remaining amount without degrading the image quality, as well as a process cartridge and an electrophotographic image forming apparatus.
It is another object of the invention to provide a developing device capable of further enhancing the detection accuracy of the creation of xe2x80x9cblank areas in an imagexe2x80x9d without exerting any influence on an image, as well as a process cartridge and an electrophotographic image forming apparatus.
It is still another object of the invention to provide a developing device, a process cartridge, and an electrophotographic image forming apparatus, which comprises a developer bearing member for supplying developer to an electrophotographic photosensitive member to develop the electrostatic latent image formed on the electrophotographic photosensitive member; a developer regulating member for regulating the amount of developer adhering to the surface of the developer bearing member; an electrode member arranged in the traveling route of the developer removed from the surface of the developer bearing member by the developer regulating member to guide the traveling developer toward a direction away from the developer bearing member; and a developer in-flow restricting member arranged for preventing the developer from flowing into a side of a surface of the developer regulating member opposite to a surface of the developer regulating member opposed to the developer bearing member.
These and other objects, features and advantages of the present invention will become more apparent upon consideration of the following description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings.